• Auto merge of #45 - danlrobertson:tex_image, r=metajack

    Implement copyTexImage2D, copyTexSubImage2D and texSubImage2D
    
    Implement copyTexImage2D, copyTexSubImage2D and texSubImage2D and add rules to the `.gitignore` for vim users. Let me know if I missed anything!
    
    Blocked by: servo/gleam#80
    
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    bors-servo committed Apr 28, 2016